The full nomenclature of the subject matter of the present invention involves extremely long terms. It is customary for those skilled in the art to abbreviate these terms in a manner well known to them. These general and customary abbreviations are set forth herein below and may be utilized in the text of this specification.
Abbreviations:
RT, reverse transcriptase
A, adenosine or adenylate or adenylyl cordycepin or C or 3'-dA, 3'-deoxyadenosine(3'-deoxyadenylate)
ara-A, 9-.beta.-D-arabinofuranosyladenine
EHNA, erthyro-9-(2-hydroxy-3-nonyl)adenine
A-3'-amino, 3'-amino-3'-deoxyadenosine tubercidin, 4-amino-7(.beta.-D-ribofuranosyl)pyrrolo-[2,3-d]pyrimidine
3'-dATP, 3'-deoxyadenosine triphosphate
ATP, adenosine triphosphate
I, inosine or inosinate or inosinylyl
Xylo-A or xyloadenosine, 9-.beta.-D-xylofuranosyladenine
dCF or 2'-deoxycoformycin, (R)-3-(2-deoxy-.beta.-D-erythropentofuranosyl)-3,6,7,8-tetrahydroimidazo[4 ,5-d][1,3]diazepine-8-ol
2-5A or 2', 5'-oligo(A) or 2', 5'-oligoadenylate, oligomer of adenylic acid with 2', 5'-phosphodiester linkages and a triphosphate at the 5'-end
C, cordecypin
2', 5'-cordycepin analog or 2', 5'-oligocordycepin, oligomer of 3'-deoxyadenylic acid with 2', 5'-phosphodiester linkages and a triphosphate at the 5'-end
2', 5'-A.sub.n or core oligomer, oligomer of adenylic acid with 2', 5'-phosphodiester linkages
2', 5'-A.sub.3 or 2', 5'-adenylate trimer core, adenylyl-(2', 5')adenylyl(2', 5')adenosine
2', 5'-A.sub.4 or 2', 5'-adenylate tetramer core, adenylyl-(2', 5') adenylyl (2', 5') adenylyl (2', 5') adenosine
2', 5'-3'dA.sub.3 or 2', 5'-C-C-C or 2', 5'-cordycepin trimer core, 3'-deoxyadenylyl (2', 5')3'-deoxyadenylyl-(2', 5')3'-deoxyadenosine
2', 5'-C-C-C-C or 2', 5'-cordycepin tetramer core, 3'-deoxyadenylyl (2', 5')3'-deoxyadenylyl (2', 5')3'-deoxyadenylyl-(2', 5')3'-deoxyadenosine
3', 5'-A.sub.3, adenylyl (3', 5') adenylyl (3', 5') adenosine 2', 5'-I.sub.3 or 2', 5'-inosine trimer core, inosinylyl-(2', 5')inosinylyl(2', 5')inosine
dd benz, benzimidazylyl(2',5')5,6-dichlorobenzimidazole riboside,
EBV, Epstein-Barr virus
EBNA, Epstein-Barr virus associated early nuclear antigen
HBV, hepatitis B virus
HIV, human immunodeficiency virus, including HIV-1, HIV-2, and all other HIV subtypes
HBLV, human B-cell lymphotropic virus
HTLV, human T-cell leukemia virus, including HTLV-I, HTLV-II and HTLV-III, and all other HTLV sub-types
IFN.alpha.: .alpha.-interferon
rIFN-.alpha.A: recombinant .alpha.-interferon
dsRNA: double-strand ribonucleic acid
2', 5'-A-A-Tu, adenylyl(2', 5')adenylyl(2', 5')tubercidin
2', 5'-Tu-Tu-Tu, 2', 5'-tubercidylyl(2', 5'1(2', 5')tubercidin
2', 5'-A-A-ara-A, adenylyl (2', 5')adenylyl (2', 5') ara-A
2', 5'-C-C-A, 3'-deoxyadenylyl (2', 5')3'deoxyadenylyl (2', 5') adenosine
2', 5'-A-C-C, adenylyl (2', 5') 3'-deoxyadenylyl-(2', 5') 3'-deoxyadenosine
2', 5'-A-A-C adenylyl (2', 5') adenylyl (2', 5')3'-deoxyadenosine
2', 5'-C-A-C, 3'-deoxyadenylyl (2', 5') adenylyl (2', 5')-3'-deoxyadenosine
2', 5'-C-C-A, 3'-deoxyadenylyl (2', 5')adenosine
2', 5'-A-C-A, adenylyl (2', 5')3'-deoxyadenylyl (2', 5')adenosine 2', 5'-xylo-A.sub.3, xyloadenylyl (2', 5')xyloadenylyl-(2', 5') xyloadenosine
2', 5'-xylo-A.sub.4, xyloadenylyl(2', 5') xyloadenylyl-(2', 5') xyloadenylyl (2', 5')xyloadenosine
Ac, acetyl
Bz, benzyl
MMTr, 5'-O-p-methoxytrityl
2', 5'-trityl-C.sub.3, 5'-O-p-methoxytrityl-3'-deoxyadenylyl (2', 5') 3'-deoxyadenylyl (2', 5') 3'-deoxyadenosine
2',5'-trityl-A.sub.3, 5'-O-p-methoxytrityladenylyl(2', 5')adenylyl-(2', 5')adenosine
2',5'-C-C-dCF, 3'-deoxyadenylyl(2', 5')3'-deoxyadenylyl-(2', 5')2'-deoxycoformycin
2', 5'-A-A-A-3'-amino, adenylyl(2', 5')adenylyl-(2',5')3'-amino-3'-deoxyadenosine
SiTBD, t-butyldimethylsilyl or --Si(CH.sub.3).sub.2 C(CH.sub.3).sub.3
2',5'-A.sub.(Si) -A.sub.(Si) -A, 3'-O-t-butyldimethylsilyladenylyl-(2',5')3'-O-t-butyldimethylsilyladenylyl (2', 5')adenosine
2', 5'-A-A-A-3'-O-methyl, adenylyl(2', 5')adenylyl-(2',5')3'-O-methyladenosine
2', 5'-A-A-A-3'-O-pentyl, adenylyl(2', 5')adenylyl-(2',5')3'-O-pentyladenosine
2', 5'-A-A-A-3'-O-hexyl, adenylyl(2', 5')adenylyl-(2',5')3'-O-hexyladenosine
2', 5'-A-A-A-3'-O-heptyl, adenylyl(2', 5')adenylyl-(2', 5')3'-O-heptyladenosine
2', 5'-EHNA-A-A, erythro-9-(2-hydroxy-3-nonyl)-adenylyl(2', 5')adenylyl(2', 5')adenosine
The abbreviation for the "tetramer" compounds comprising the adenylyl (A) and 3'deoxyadenylyl (C) moieties is illustrated by the following:
2', 5'-A-A-C-C, adenylyl(2', 5')adenylyl(2', 5')3'-deoxyadenylyl(2', 5')3'-deoxyadenosine
The above compounds are also abbreviated without the 2'-5' prefix, without hyphens and without the -3' suffix; hence 2'-5'-C-C-C-3' is also abbreviated CCC.
With the expansion of the knowledge of the antiviral state induced by interferon, attention has been focused on the chemical and enzymatic synthesis and biological properties of the 2', 5'-oligoadenylates as mediators of the antiretroviral response. 2', 5'-Oligo(A) is a component of a natural, broad-spectrum antiviral defense mechanism in plants and animals. The 2-5A pathway, also known as the 2-5A/RNase L pathway or antiviral system, is widely accepted to be involved in the antiviral mechanism of interferon, and is also involved in the regulation of cell growth and differentiation.
The pathway involves the activation by 2-5A of the latent endoribonuclease, RNase L (EC 3.1.27). According to that pathway shown in FIG. 1, 2-5A is synthesized from ATP by 2', 5'-oligoadenylate synthetase [ATP: (2'-5')oligo(A)-adenyl-transferase (EC 2.7.7.19)], hereinafter "2-5A synthetase". When activated by dsRNA, 2-5A synthetase converts ATP into 2-5A, i.e., a series of 2', 5'-linked oligoadenylates characterized by a 5'-terminal triphosphate. 2-5A Synthetase exists in different isoenzyme forms, is induced by interferon, but is also detectable at lower levels in the absence of interferon. 2-5A exerts its biological effects by binding to and activating its only known target enzyme, the unique 2-5A dependent endoribonuclease RNase L. The latter cleaves viral and cellular mRNA or rRNA, thereby inhibiting protein synthesis. Hovanessian et al., Eur. J. Biochem. 93:515-526 (1979); Kerr et al., Proc. Natl. Acad. Sci. USA 75:256-260 (1978). The short half-life of the authentic 2-5A molecule in biological systems is an acknowledged disadvantage in the control of viral replication. Moreover, bioactive 2-5A is inactivated by three enzymes: a relatively unspecific 2'-phosphodiesterase, a 5'-phosphatase, and a relatively specific 2', 3'-exonuclease. Some cytokines, e.g. IL-6, activate 2-5A synthetase in such a way as to cause the enzyme or particular forms of the enzyme to produce bioinactive forms of 2-5A (Bickel, M., Dveksler, G, Dieffenbach, C., W., Ruhl, S., Midura, S., B. and Pluznik, D. H., Cytokine 2:238-246 (1990) and Cohen, B., Gothelf, Y., Vaiman, D., Revel, M. and Chebath, J., Cytokine 3:83-91 (1991)).
The 2-5A synthetase/RNase L pathway is activated following viral infection by many viruses including HIV-1 (Schr oder, H. C., Wenger, R., Kuchino, Y., and M uller, W.E.G., J. Biol. Chem. 264, 5669 (1989); Schr oder, H. C., Wenger, R., Rottman, M., and M uller, W.E.G., Biol. Chem. Hoppe-Seyler 369, 985 (1988)). The activation of this pathway delays the HIV infection process. To activate RNase L, the naturally occurring 2-5A molecule requires a 5'-triphosphate, which is unstable. 2-5A molecules with 5'-monophosphates or no 5'-phosphate (core) do not activate RNase L at physiological concentrations.
"Human B-lymphotropic virus" also known as "human B-cell lymphotropic virus" (HBLV), now called HHV-6, which is characterized by a large molecular weight double-stranded DNA genome is morphologically similar to viruses of the herpes virus family, but is readily distinguishable from the known human and non-human primate herpes viruses by host range, in vitro biological effects, antigenic features and genome. Salahuddin et al., Science 234:596-601 (1986); Josephs et al., Science 234:601-602 (1986). The virus has been observed to selectively infect freshly isolated human B-cells, which are converted into large, refractile mono- or binucleated cells with nuclear and cytoplasmic inclusion bodies. HBLV is suspected to be the cause of a chronic mononucleosis-like syndrome characterized by chronic fatigue lasting more than a year.
Human immunodeficiency virus ("HIV"), also known as human T-cell leukemia virus III ("HTLV-III"), the etiologic agent of acquired immune deficiency syndrome, is a type D retrovirus. As in all retroviruses, an essential feature of HIV replication is reverse transcription of the plus-strand RNA genome into DNA, a process which requires an RNA dependent DNA polymerase, reverse transcriptase. This enzyme is viral-encoded and is found associated with genomic RNA in mature HIV virions. The exclusiveness of reverse transcriptase to retroviruses and viruses requiring a short reverse transcription step makes reverse transcriptase a major target for antiviral, and particularly for antiretroviral, therapeutic intervention.
The 2-5A synthetase/RNase L system as an antiviral cellular defense mechanism has been shown to be a promising target for antiviral chemotherapy, particularly due to its interaction with double-stranded segments within viral genomes or transcripts such as the HIV-1RNA genome (Lengyel, P., Annu. Rev. Biochem. 51,251 (1982); Pestka, S., ed., Methods Enzymol. 118,119 (1986); Lengyel, P., J. Interferon Res. 7, 511 (1987); Sen, G. C., Prog. Nucleic Acid Res. Molec. Biol. 27, 105 (1982)). However, what is needed are derivatives of 2-5A which will override degradation by enzymes which inactivate authentic 2-5A. What is needed is a method for controlling HIV, chronic fatigue caused by HBLV, and other viral or cytokine-induced disease states characterized by a 2-5A pathway defect using compounds that are more metabolically stable and active than authentic 2-5A. What is needed is a method for treatment of viral infection which utilizes compounds which have broad spectrum, dual action, that is, compounds which both activate the 2-5A pathway and inhibit the activity of viral DNA polymerase.